I did a lab biology project on seed germination and the results weren't as expected. pH 5 worked better than pH 6 or 7 which seemed weird because surely it would be too acidic. I've been trying to find an explanation as to why I got these results and I think, possibly, it's to do with the buffer solutions I used. What could be in the buffer solution which might give these results.

Thanks in advance for any help!

To understand why pH 5 worked better than pH 6 or 7 in your seed germination experiment, you're right to consider the buffer solutions you used. Buffer solutions are solutions that resist changes in pH when small amounts of acid or base are added. They typically contain a weak acid and its conjugate base or a weak base and its conjugate acid.

The unexpected result in your experiment could be due to the specific buffer solution you used for pH 5. Buffer solutions function by maintaining a stable pH within a certain range. In this case, it seems that pH 5 was more favorable for seed germination compared to pH 6 or 7.

There are a few possible explanations for this observation:

1. Phytohormones: Buffer solutions may contain certain chemicals or components that act as phytohormones, which are naturally occurring compounds that influence plant growth and development. These phytohormones can affect seed dormancy, germination, and seedling growth.

2. Nutrient availability: Buffer solutions can influence the availability of nutrients for plant growth. pH levels can affect the solubility and availability of essential nutrients required for seed germination, such as phosphorus, potassium, and calcium. pH 5 might have provided the optimal conditions for nutrient uptake and utilization by the seeds.

3. Microbial activity: pH levels can impact microbial activity in the soil. Certain microorganisms present in the soil play a crucial role in the decomposition of organic matter, nutrient cycling, and growth promotion of plants. pH 5 might have supported a more favorable microbial community for seed germination compared to pH 6 or 7.

To gain a deeper understanding of why pH 5 resulted in better seed germination, it would be beneficial to investigate the specific components and chemistry of the buffer solution used at pH 5. Analyzing its composition and considering the potential impacts on phytohormones, nutrient availability, and microbial activity can provide valuable insights into your experimental results.